Battered Japanese nuclear plant overwhelmed in disaster; changes being made here to prevent similar catastrophe
Waterford - Nearly three years after a major earthquake and tsunami caused the Fukushima Daiichi nuclear power station disaster, Millstone Power Station here is undergoing more than $10 million in equipment and facilities upgrades to enable it to better withstand natural disasters.
The work is taking place at Millstone and the nation's other nuclear power plants after orders were issued by the Nuclear Regulatory Commission in March 2012 for enhancements of safety and emergency response capabilities in response to the 2011 disaster in Japan, in which three reactor cores melted down and large amounts of radiation were released.
The orders issued in 2012 were the first of what the NRC expects will be at least three sets of Fukushima-related directives to nuclear power plants, NRC spokesman Neil Sheehan said Wednesday. Analysis required to determine the extent of further modifications needed at plants is expected to be completed in the next two years, he said.
"We still have a significant amount of work to do on the recommendations," he said.
Ken Holt, spokesman for Millstone owner Dominion, said the largest Fukushima-related project is construction of a 10,000-square-foot reinforced concrete storage dome on power plant property that had been used as a contractor parking lot. The Connecticut Siting Council approved the project last month, and Dominion is preparing to submit an application for a building permit to the town and start construction this spring, he said. The dome would house emergency equipment required by the NRC that could be used to keep critical systems running at Millstone's two operating reactors in the event of power outages, storm surges and other emergencies.
The dome will be 38 feet high and 115 feet in diameter, built to withstand hurricanes, flooding and earthquakes. Engineering specifications call for the dome to be constructed at a site about 30 feet above sea level and to resist collapse in winds up to 300 mph and earthquakes of the same magnitude as the Millstone 3 plant was built to withstand, Holt said.
"It will be at a site that's easy to access for plant operators, but removed from the reactors," Holt said.
David Lochbaum, director of the nuclear safety project for the Union of Concerned Scientists, a nonprofit watchdog group, said the NRC should have required Millstone to build the dome to higher earthquake-proof standards than the Millstone 3 plant. Even though the East Coast is not a seismically active area, the Fukushima disaster illustrates that planning for higher levels of disaster than seem likely is prudent, he said.
In the unlikely scenario that a higher magnitude earthquake collapsed Millstone 3, he said, the dome would also collapse, making it difficult or impossible for workers to access the emergency equipment they would need, Lochbaum said.
"Fukushima showed we need to do more," he said.
The dome would house additional portable pumps and generators the NRC is requiring plants to keep on site, as well as bulldozers, ATVs and other heavy equipment that would be needed to remove fallen trees and other debris to gain access to the plant after a storm. Nuclear power stations were already required to have enough of this equipment to handle an emergency at one plant at a time, but the new rules require them to have enough to handle multiple emergencies at more than one plant simultaneously, Lochbaum noted. He believes the NRC's directives should go further to ensure that the equipment would be accessible if there was damage to a reactor core.
In addition to the dome project, Millstone staff and contractors are also adding new electrical connections in critical plant systems for portable generators, pumps and other emergency equipment. Twenty-five new connections are being added to the two plants, Holt said. The work will be completed during the planned outages of Unit 2 this spring and Unit 3 in the fall, he said. The emergency equipment would ensure that monitoring systems, cooling water receptacles and other areas of the plant can be supplied with the power and water needed to maintain plant safety in a disaster.
Worker training and testing of the new emergency equipment will be incorporated into routine professional education and testing programs at the plant, Holt said. The new testing and training, Lochbaum noted, is not being required by the NRC but is being added voluntarily by Dominion and other plant owners. He is critical of the NRC for not making it a requirement. That would prevent plant owners from eliminating it in the future due to budget constraints or other factors, he said.
$10 million dome
Because the Fukushima plants lost their ability during the disaster to keep water in the spent fuel pools cool, the NRC is also requiring plants to install new instruments to prevent that from happening if a disaster occurred at a plant in the United States. At Millstone, battery-operated gauges are being added to the spent fuel pool that would continue monitoring water levels and temperatures even after loss of power, Holt said.
Altogether, the Fukushima projects and equipment at Millstone are costing Dominion "in the tens of millions," Holt said, though he did not provide an exact amount. Lochbaum said the dome alone will cost about $10 million. Millstone and other plants have been given until December 2016 to complete the work. Thus far, most plants appear to be on schedule, although some are behind on requirements pertaining to adding additional flood protection barriers, Lochbaum said.
"But we want to get it done right versus meeting some arbitrary deadline," he said.
Millstone, located on Long Island Sound, is among power stations required to complete a higher level of flood hazard evaluation than plants located away from major waterways, noted Sheehan of the NRC. Millstone's assessment must be completed by March 2015, including a description of how it would reduce flood risk. The results may require the installation of additional flood barriers or other equipment. And while some seismic risk analysis has been done, Millstone and other plants are also required to complete a higher-level risk analysis by 2019.
Overall, Sheehan said, "the majority of the work is on track." He added, however, that plants will be making modifications in response to lessons learned from the Fukushima disaster for many years to come.
"All of this will play out over a number of years," he said.